A splint for fixing distal radius fracture

Abstract

The present application relates to the technical field of medical devices, in particular to a splint for fixing distal radius fracture, which comprises an outer splint, an inner splint, a belt and an adjusting assembly. The inner splint has a palm-adhering part shaped according to the palm of a human body and an inner-arm-adhering part shaped according to the inner side of a lower arm. The outer splint has a back-adhering part shaped according to the back of a human body and an outer-arm-adhering part shaped according to the outer side of a lower arm. The belt is wrapped around the outer periphery of the outer splint and the inner splint, one end of the belt is connected to the outer splint, and the adjusting assembly is arranged on the outer splint, the other end of the belt not connected to the outer splint is inserted into the adjusting assembly, and the adjusting assembly is adapted to adjust the length of the belt inserted therein. Compared with other splints in the prior art, the splint provided in the present application has more convenient operability, the tightness of the splint can be adjusted by a patient alone, and the splint has the advantages of comfortable wearing, high stability and reliability, low manufacturing cost and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a splint for fixing distal radius fracture. BACKGROUND

[0002] Distal radius fracture is a common clinical disease, accounting for more than 20% of all body fracture cases. In clinical external fixation therapy for distal radius fracture, the most common method is to use plaster fixation. However, the plaster fixation method has multiple defects. First, due to its material itself, it has poor air permeability. Second, during the entire recovery period, as the degree of edema subsides, the patient needs to go back and forth to the hospital for plaster mold disassembly and secondary tightening. Third, the plaster material cannot be recycled and reused, causing serious environmental pollution.

[0003] Therefore, there are many external fixation splints for radius fracture in the prior art. For example, a novel fixed movable orthopedic splint is disclosed in Chinese Patent No. CN209187139U, which comprises an orthopedic splint body, a rear arm pad plate provided at one end of the orthopedic splint body, a rear arm locking belt provided at the top of the rear wall pad plate, movable fixing plates provided at both sides of the center of the splint body, a movable rotating shaft provided on the movable fixing plate, a rotating limiting block provided at the top end of the movable fixing plate, a wrist pad plate provided at the other end of the orthopedic splint body, a wrist band provided at the top of the wrist pad plate, and a forearm pad plate provided at one side of the wrist pad plate. The orthopedic splint better solves the problems of air permeability and adjustability of the plaster board.

[0004] However, such special splints still have a big defect in actual use, that is, professional personnel is still needed to participate in the process of wearing or adjusting the splint, and the patient cannot adjust the splint alone. At the same time, the comfort of the above-mentioned splint is still insufficient when worn. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to overcome the problems of inconvenient adjustment and insufficient comfort of the existing splint for fixing radius fracture, and to provide a more comfortable and convenient-to-adjust splint for fixing distal radius fracture.

[0006] To solve the above technical problems, the technical solution provided by the present application is as follows:

[0007] A splint for fixing distal radius fracture, comprising:

[0008] an inner splint having a palm-adhering part shaped to fit the palm of a human body and an inner arm-adhering part shaped to fit the inner side of a forearm;

[0009] The outer clamping plate is provided with a hand back fitting part and an outer arm fitting part; the inner clamping plate and the outer clamping plate are suitable for clamping the human arm and part of the palm after buckling;

[0010] The belt is arranged around the outer clamping plate and the inner clamping plate, and one end of the belt is connected with the outer clamping plate;

[0011] The adjusting assembly is arranged on the outer clamping plate, and the end of the belt not connected with the outer clamping plate is inserted into the adjusting assembly; the adjusting assembly is suitable for adjusting the length of the belt inserted thereinto.

[0012] As a preferred technical solution, the adjusting assembly comprises:

[0013] The gear is rotatably arranged on the outer clamping plate; the belt is provided with a gear rack suitable for cooperating with the gear along the length direction of the belt;

[0014] The knob is coaxially fixedly arranged with the gear, and the gear is suitable for being synchronously rotated under the driving of the knob;

[0015] The one-way preventing mechanism is arranged between the knob and the gear, and the one-way preventing mechanism is suitable for preventing the belt from being withdrawn in the direction of being taken out of the adjusting assembly.

[0016] As a preferred technical solution, the one-way preventing mechanism comprises:

[0017] The gear ring is arranged on the outer clamping plate and arranged around the outer periphery of the rotation shaft of the gear and the knob;

[0018] The preventing wheel is arranged on the rotation shaft of the gear and the knob and is suitable for being coaxially rotated with the gear and the knob; the preventing wheel is provided with an abutting surface suitable for cooperating with the gear ring, and the abutting surface is suitable for abutting on the tooth surface of the gear ring when the belt is taken out of the adjusting assembly.

[0019] As a preferred technical solution, the preventing wheel is provided with a plurality of elastic arms, the abutting surface is arranged at the end of the elastic arm, and the side of the elastic arm towards the gear ring is further provided with a sliding pressure surface; the sliding pressure surface is suitable for slidingly contacting the tooth surface of the gear ring and compressing the elastic arm to the central position of the preventing wheel when the preventing wheel is rotated in the direction of tightening the belt.

[0020] As a preferred technical solution, the elastic arm is further provided with a guide groove, the knob is fixedly provided with a latch pin, the latch pin is arranged in the guide groove, and the latch pin is suitable for compressing the guide groove and driving the elastic arm to shrink to the central part of the preventing wheel when the knob is rotated in the direction of taking out the belt.

[0021] As a preferred technical scheme, the outer clamping plate is provided with a base plate, a gap suitable for inserting the belt is formed between the base plate and the outer surface of the outer clamping plate, the gear is mounted on the inner side of the base plate, the gear ring is integrally formed on the outer side of the base plate, the blocking wheel is mounted in the gear ring, and the knob is mounted on the outer side of the gear ring and the blocking wheel.

[0022] As a preferred technical scheme, the gear is integrally formed with a flat rod, and the blocking wheel and the knob are sleeved on the flat rod.

[0023] As a preferred technical scheme, one of the outer clamping plate or the inner clamping plate is formed with an insertion plate at the joint with the other, and the one which is not provided with the insertion plate is provided with an insertion groove suitable for cooperating with the insertion plate.

[0024] As a preferred technical scheme, the belt has two belts, which are respectively arranged at positions corresponding to the wrist part and the middle part of the forearm of the human body.

[0025] As a preferred technical scheme, the outer clamping plate and the inner clamping plate are both hollow structures.

[0026] The technical effect of the above technical scheme is that:

[0027] 1. The clamping plate provided by the application comprises an outer clamping plate, an inner clamping plate, a belt and an adjusting assembly. The inner clamping plate has a palm abutting part corresponding to the palm of the human body and an inner arm abutting part corresponding to the inner side of the forearm; the outer clamping plate has a back abutting part corresponding to the back of the human body and an outer arm abutting part corresponding to the outer side of the forearm; the inner clamping plate and the outer clamping plate are suitable for clamping the forearm and part of the palm of the human body after being buckled; the belt is arranged around the outer periphery of the outer clamping plate and the inner clamping plate, one end of the belt is connected with the outer clamping plate; the adjusting assembly is arranged on the outer clamping plate, and the other end of the belt which is not connected with the outer clamping plate is inserted into the adjusting assembly; the adjusting assembly is suitable for adjusting the length of the belt inserted therein.

[0028] In the above structure, the outer clamping plate and the inner clamping plate are designed to correspond to the palm and the arm of the human body, which on the one hand improves the comfort of the wearer, and on the other hand, the design of the corresponding part can ensure that the patient can receive uniform pressure on the palm and the arm during the fixed recovery period after the fracture, which is beneficial to the recovery of the patient. On the other hand, by using the design of the belt and the adjusting assembly, the patient can adjust the tightness of the belt by himself, avoiding frequent visits to the hospital, saving medical resources, and also reducing the economic burden of the patient.

[0029] 2. The splint, the adjusting assembly comprises a gear, a knob and a one-way preventing mechanism. The gear is rotatably installed on the outer splint; the strap is provided with a rack along the length direction of the strap, the rack is suitable for cooperating with the gear; the knob is coaxially fixedly installed with the gear, the gear is suitable for synchronously rotating under the driving of the knob; the one-way preventing mechanism is arranged between the knob and the gear, the one-way preventing mechanism is suitable for preventing the strap from being pulled back to the direction of being separated from the adjusting assembly. The one-way preventing mechanism comprises a gear ring and a preventing wheel. The gear ring is arranged on the outer splint and surrounds the outer periphery of the rotating shaft of the gear and the knob; the preventing wheel is installed on the rotating shaft of the gear and the knob and is suitable for coaxially rotating with the gear and the knob; the preventing wheel is provided with a suitable abutting surface for cooperating with the gear ring, the abutting surface is suitable for abutting on the tooth surface of the gear ring when the strap is separated from the adjusting assembly; the outer periphery of the preventing wheel is provided with a plurality of elastic arms, the abutting surface is arranged at the end of the elastic arm, and the side of the elastic arm towards the gear ring is further provided with a sliding pressure surface, the sliding pressure surface is suitable for slidingly contacting the tooth surface of the gear ring and compressing the elastic arm to the central position of the preventing wheel when the preventing wheel rotates to the direction of tightening the strap.

[0030] In the above structure, the gear can be rotated by operating the knob, thereby driving the strap to move; the one-way preventing mechanism can prevent the strap from being separated without external force interference. Specifically, when the knob rotates to the direction of tightening the strap, the abutting surface at the end of the elastic arm rotates synchronously with the preventing wheel, the elastic arm is compressed to the center under the action of the sliding pressure surface and the teeth of the gear ring, and the abutting surface is switched and abuts on the next tooth. In this way, the function of the one-way preventing mechanism is realized. The above scheme has the advantages that the tightening of the strap can be realized by the operation of the patient with one hand, and the operation is very convenient.

[0031] 3. The splint, the elastic arm is further provided with a guide groove, the knob is fixedly provided with a catch pin, the catch pin is arranged in the guide groove, and the catch pin is suitable for compressing the guide groove and driving the elastic arm to shrink to the central part of the preventing wheel when the knob rotates to the direction of separating the strap.

[0032] In the above structure, when it is necessary to loosen the strap, the knob is reversely rotated, the catch pin on the knob can compress the guide groove due to the elasticity of the flat rod between the knob and the gear, the elastic arm is inwardly shrunk, the abutting surface is forced to leave the teeth on the gear ring, and then the preventing wheel can rotate to the direction of loosening the strap. Through the above scheme, it can be seen that the design of the catch pin and the guide groove solves the problem of how to loosen the gear ring of the preventing wheel by utilizing the elasticity of the flat rod, and the structure is simple, the operation is convenient, and the stability is reliable.

[0033] 4. The clamp provided by the present invention has an insert plate formed at the joint between the outer clamp plate and the inner clamp plate and the other clamp plate, and the outer clamp plate or the inner clamp plate without the insert plate has a slot suitable for cooperating with the insert plate. Through the cooperation of the insert plate and the slot, the outer clamp plate and the inner clamp plate can be more easily aligned when joined, and when a certain gap needs to be loosened, the insert plate and the slot can also ensure that the outer clamp plate and the inner clamp plate do not misalign, ensuring that the fixed posture of the arm and wrist does not change.

[0034] 5. The clamping plate provided by the present invention has both the outer clamping plate and the inner clamping plate having a hollow structure. The hollow structure can reduce material consumption when manufacturing the clamping plate by injection molding or 3D printing, and can also achieve the effects of weight reduction and breathability.

[0035] In summary, the splint provided in this invention is more convenient to operate than other splints in traditional technology. The patient can adjust the tightness of the splint by a single person. It also has the advantages of comfortable wearing, high stability and reliability, and low manufacturing cost. Attached Figure Description

[0036] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0037] Figure 1 This is a perspective view of the clamping plate provided in Embodiment 1 of the present invention;

[0038] Figure 2 for Figure 1 The image shown is a 3D view of the splint worn on the arm.

[0039] Figure 3 for Figure 1 A three-dimensional structural diagram of the upper and lower clamping plates in the separated state.

[0040] Figure 4 for Figure 1 Exploded view of the adjusting assembly in the clamping plate shown;

[0041] Figure 5 for Figure 4 The diagram shows a three-dimensional view of the back of the knob and stop wheel in the adjustment assembly shown.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1 - outer splint, 2 - inner splint, 3 - palm fitting part, 4 - inner arm fitting part, 5 - back of hand fitting part, 6 - outer arm fitting part, 7 - belt, 8 - knob, 9 - gear, 10 - gear ring, 11 - blocking wheel, 12 - abutting surface, 13 - sliding pressure surface, 14 - guide groove, 15 - catch pin, 16 - base plate, 17 - flat bar, 18 - insertion plate, 19 - insertion groove, 20 - rack, 21 - elastic arm. DETAILED DESCRIPTION

[0044] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0045] In the description of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0046] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0047] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0048] Embodiment:

[0049] Reference Figure 1 and Figure 2, the present embodiment provides a splint for fixing distal radius fracture, which comprises an outer splint 1, an inner splint 2, a belt 7 and an adjusting assembly. The inner splint 2 has a palm fitting part 3 corresponding to the palm of human body and an inner arm fitting part 4 corresponding to the inner side of the forearm; the outer splint 1 has a back fitting part 5 corresponding to the back of human body and an outer arm fitting part 6 corresponding to the outer side of the forearm; the inner splint 2 and the outer splint 1 are adapted to clamp the forearm and part of the palm of human body after being buckled; the outer splint 1 and the inner splint 2 are both hollow structures. The outer splint 1 and the inner splint 2 are designed to correspond to the palm and the arm of human body, which can improve the comfort of the wearer and ensure that the palm and the arm of the patient can be evenly pressed during the fixing and recovery period after fracture, which is beneficial to the recovery of the patient. Meanwhile, the hollow structure can ensure the air permeability and lightness.

[0050] Referring to Figure 1 and Figure 2 , the belt 7 is wrapped around the outer periphery of the outer splint 1 and the inner splint 2. The belt 7 has two, which are respectively arranged at positions corresponding to the wrist part of human body and the middle part of the forearm. One end of the belt 7 is connected with the outer splint 1; the adjusting assembly is arranged on the outer splint 1, and the other end of the belt 7 not connected with the outer splint 1 is inserted into the adjusting assembly; the adjusting assembly is adapted to adjust the length of the belt 7 inserted thereinto. Specifically, the end of the belt 7 connected with the outer splint 1 is provided with a clamping strip, and the outer splint 1 is provided with a gap adapted to allow the belt 7 to pass through, the belt 7 passes through the gap and is clamped on the end face of the gap by the clamping strip at the tail end. The other end of the belt 7 is inserted into the adjusting assembly, and the adjusting assembly comprises a base plate 16 arranged on the outer splint 1, the base plate 16 also has a gap adapted to allow the belt 7 to be inserted between the outer surface of the outer splint 1 and the base plate 16, and the belt 7 is inserted into the gap to realize the engagement of the rack 20 and the gear 9. Specifically, the gear 9 is installed on the inner side of the base plate 16, and a rectangular frame extending in the length direction is formed on the belt 7, the upper edge of the rectangular frame is the rack 20, and in use, the gear 9 is inserted into the rectangular frame to cooperate with the rack 20. Such design can ensure that the gear 9 is located in the rectangular frame and is limited by the rectangular frame, so as to avoid the disengagement of the rack 20 and the gear 9. By using the design of the belt 7 and the adjusting assembly, the patient can adjust the tightness of the belt 7 by himself, which can avoid frequent visits to the hospital, save medical resources and reduce the economic burden of the patient.

[0051] Referring to Figure 4The adjusting assembly comprises a gear 9, a knob 8 and a one-way preventing mechanism. The gear 9 is rotatably installed on the base plate 16 of the outer clamping plate 1; a flat rod 17 is integrally formed on the gear 9, and the preventing wheel 11 and the knob 8 are sleeved on the flat rod 17. The one-way preventing mechanism comprises a gear ring 10 and the preventing wheel 11, which are arranged between the knob 8 and the gear 9, and the preventing wheel 11 is installed on the flat rod 17 and rotates synchronously with the gear 9 and the knob 8. The gear ring 10 is arranged on the base plate 16 of the outer clamping plate 1, and the preventing wheel 11 is sleeved in the gear ring 10. The preventing wheel 11 is installed on the rotating shaft of the gear 9 and the knob 8 and is adapted to rotate coaxially with the gear 9 and the knob 8; the preventing wheel 11 is provided with an abutting surface 12 adapted to abut against the tooth surface of the gear ring 10, and the abutting surface 12 is adapted to abut against the tooth surface of the gear ring 10 when the belt 7 is pulled out of the adjusting assembly. A plurality of elastic arms 21 are arranged on the outer periphery of the preventing wheel 11, and the abutting surface 12 is arranged at the end of the elastic arms 21; a sliding pressure surface 13 is further arranged on the side of the elastic arms 21 facing the gear ring 10, and the sliding pressure surface 13 is adapted to slide and contact the tooth surface of the gear ring 10 and compress the elastic arms 21 to the central position of the preventing wheel 11 when the preventing wheel 11 rotates in the direction of tightening the belt 7. In use, the gear 9 can be rotated by operating the knob 8, thereby driving the belt 7 to move; and the one-way preventing mechanism can prevent the belt 7 from being pulled out without external force interference. Specifically, when the knob 8 rotates in the direction of tightening the belt 7, the abutting surface 12 at the end of the elastic arms 21 rotates synchronously with the preventing wheel 11, the elastic arms 21 are compressed to the center under the action of the sliding pressure surface 13 and the teeth of the gear ring 10, and the abutting surface 12 is switched and abuts on the next tooth. In this way, the one-way preventing mechanism is realized. The above scheme has the advantages that the tightening of the belt 7 can be realized by the patient operating with one hand, and the operation is very convenient.

[0052] Referring to Figure 5 In order to ensure that the gear ring 10 can loosen the belt 7 under the manual operation of the patient, a guide groove 14 is further arranged on the elastic arm 21, a catch pin 15 is fixed on the knob 8, the catch pin 15 is arranged in the guide groove 14, and the catch pin 15 is adapted to compress the guide groove 14 and drive the elastic arm 21 to shrink to the central part of the preventing wheel 11 when the knob 8 rotates in the direction of pulling out the belt 7. When it is necessary to loosen the belt 7, the knob 8 is reversely rotated, the flat rod 17 between the knob 8 and the gear 9 has a certain elasticity, the knob 8 can be independently rotated by a certain angle by means of the elasticity, therefore the catch pin 15 on the knob 8 will compress the guide groove 14, and then the elastic arm 21 will shrink inward, forcing the abutting surface 12 to move away from the teeth on the gear ring 10, and then the preventing wheel 11 can rotate in the direction of loosening the belt 7. Through the above scheme, it can be seen that the design of the catch pin 15 and the guide groove 14 solves the problem of how to loosen the gear ring 10 by the preventing wheel 11 by utilizing the elasticity of the flat rod 17 itself, which is simple in structure, convenient in operation and stable and reliable.

[0053] With reference to Figure 3 One of the outer splint 1 or the inner splint 2 is shaped with an insertion plate 18 at the jointing part with the other one, and the one of the outer splint 1 or the inner splint 2 without the insertion plate 18 is provided with an insertion slot 19 adapted to cooperate with the insertion plate 18. Through the cooperation of the insertion plate 18 and the insertion slot 19, the outer splint 1 and the inner splint 2 can be more conveniently aligned when being spliced, and when a certain gap needs to be loosened, the insertion plate 18 and the insertion slot 19 can also ensure that the outer splint 1 and the inner splint 2 do not dislocate, ensuring that the fixed posture of the arm and wrist does not change.

[0054] Obviously, the above embodiments are only examples for clearly illustrating, but not limitation to the embodiments. Other different forms of changes or variations can be made on the basis of the above description for those of ordinary skill in the art. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A splint for fixing distal radius fractures, characterized in that, include: The inner splint has a palm-fitting part that conforms to the human hand and an inner arm-fitting part that conforms to the inner side of the forearm; The outer clamp has a back-of-hand conforming part that conforms to the back of the human hand and an outer arm conforming part that conforms to the outer side of the forearm; the inner clamp and the outer clamp are adapted to clamp the human forearm and part of the palm after being fastened. A strap is wrapped around the outer and inner clamping plates, with one end of the strap connected to the outer clamping plate; An adjustment assembly is provided on the outer clamp, and the end of the strap that is not connected to the outer clamp extends into the adjustment assembly; The adjustment component is adapted to adjust the length of the strap extending therein; The adjustment component includes: A gear is rotatably mounted on the outer clamping plate; a rack suitable for cooperating with the gear is provided on the belt along the length direction of the belt; A knob is fixedly mounted coaxially with a gear, the gear being adapted to rotate synchronously under the drive of the knob; A one-way blocking mechanism is disposed between the knob and the gear, the one-way blocking mechanism being adapted to prevent the strap from being pulled back in the direction of disengagement from the adjustment assembly; The one-way blocking mechanism includes: A gear ring is mounted on the outer clamping plate and surrounds the outer circumference of the rotation shaft of the gear and the knob; An anti-roll wheel is mounted on the rotating shaft of the gear and the knob, and is adapted to rotate coaxially with the gear and the knob; the anti-roll wheel is provided with a contact surface adapted to cooperate with the gear ring, and the contact surface is adapted to abut against the tooth surface of the gear ring when the belt is disengaged from the adjustment assembly; The outer periphery of the stop wheel is provided with a plurality of elastic arms, the abutting surface is provided at the end of the elastic arm, and a sliding pressure surface is also provided on the side of the elastic arm facing the tooth ring. The sliding pressure surface is adapted to slide into contact with the tooth surface of the tooth ring and press the elastic arm to contract toward the center position of the stop wheel when the stop wheel rotates in the direction of tightening the belt. The elastic arm is also provided with a guide groove, and the knob is fixed with a trip pin. The trip pin is placed in the guide groove and is adapted to press the guide groove and drive the elastic arm to retract toward the center of the stop wheel when the knob is rotated in the direction of disengaging from the belt. A flat rod is integrally formed on the gear, and the stop wheel and knob are fitted onto the flat rod; The flat rod is elastic.

2. The splint for fixing distal radius fractures according to claim 1, characterized in that, The outer clamp is provided with a base plate, and there is a gap between the base plate and the outer surface of the outer clamp plate suitable for inserting the strap. The gear is installed on the inner side of the base plate, the gear ring is integrally formed on the outer side of the base plate, the stop wheel is installed in the gear ring, and the knob is installed on the outer side of the gear ring and the stop wheel.

3. A splint for fixing distal radius fractures according to claim 1, characterized in that, One of the outer or inner clamping plates has an insert plate formed at the joint with the other, and the outer or inner clamping plate without an insert plate has a slot suitable for cooperating with the insert plate.

4. A splint for fixing distal radius fractures according to claim 1, characterized in that, The straps are two in number, and are respectively positioned at the wrist and mid-forearm.

5. A splint for fixing distal radius fractures according to any one of claims 1 to 4, characterized in that, Both the outer and inner clamping plates have a hollow structure.

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